Dynamics Study Of LiHF System At Low Collision Energies

During the past decades, molecular reaction dynamics has developed significantly on both experiments and theories, reaching a deeper depth of the state-to-state reaction. As a new frontier branch in the area of molecular reaction dynamics, stereodynamics has developed greatly and become a researching focus over the last two decades as it attracting great interest of many research groups. Li+HF reaction is a classical atom-diatom reaction, widely used in high energy physics, astrophysics, and plasma physical, getting achievements not only in theory but also in experiment. Only through correlating the scalar and vector properties together, can we get the whole picture of the dynamics. Reaction of Li+HF has been explored a lot on theory and experiment. Li, H and F are respectively as the lightest metal element, the lightest element and the lightest halogen element. LiHF system has only 13 electrons, which makes it easier to get an accurate potential energy surface(PES) to provide an important basis for the study of stereodynamic properties. Based on the PES built by Aguado and Paniagua whose rms is 0.515kcal/mol, in the paper, the dynamic properties of Li+HF reaction have been investigated using the quasi-classical trajectory method in depth. The PES has an obvious Van DE Waals potential well at the entrance of the reaction channel because the reactant system has strong electric dipole moment, which greatly enriches the dynamics properties.The paper is organized as following:it briefly introduces the PES and the process of dynamic in the first chapter. The second chapter describes the theory method and the basic theory of the related vector. The third chapter introduces the development of LiHF reaction and our work. As the main part of this paper, the third chapter analyzes in detail the stereodynamics of the reaction Li+HF(v=0-3, j=0-40)→LiF+H. Using the quasi-classical trajectory method, it comprehensively probes the Li+HF (v=0-3, j=0-40)→LiF+H reaction of the P(θr) describing the k-j’ correlation, the P(φr) describing the k-k’-j’ correlation distribution function and polarization dependent differential cross section (PDDCSs) of the reaction and other stereodynamic properties in combination with the collision energy, vibrational excitation and rotational excitation. The result proves that collision energy has an important influence on the P(θr,φr) in low energies, which describes the three vector correlation k-k’-j’. At the same time, it is affected by the vibration excitation. However, the effect of the vibrational excitation on the P(θr,φr) is obvious. The effect of the collision energies on the PDDCSs is different from that of high energies, moreover, the intensity of polarization scattering product rotational angular momentum polarization scattering becomes stronger with the energies increasing. Both vibrational excitation and rotational excitation have a great influence on the distribution of PDDCSs.